// TUN device support for virtual network interface

use std::net::Ipv4Addr;
use tracing::info;

pub struct TunConfig {
    pub name: String,
    pub address: Ipv4Addr,
    pub netmask: Ipv4Addr,
    pub gateway: Ipv4Addr,
    pub mtu: u16,
}

pub struct TunDevice {
    config: TunConfig,
}

impl TunDevice {
    pub fn new(config: TunConfig) -> Self {
        Self { config }
    }

    pub async fn run(&self) -> anyhow::Result<()> {
        info!("TUN device: {} ({}/{})", 
            self.config.name, 
            self.config.address, 
            self.config.netmask
        );

        // Platform-specific TUN device creation
        #[cfg(target_os = "linux")]
        {
            self.run_linux().await?;
        }

        #[cfg(target_os = "windows")]
        {
            self.run_windows().await?;
        }

        #[cfg(target_os = "macos")]
        {
            self.run_macos().await?;
        }

        Ok(())
    }

    #[cfg(target_os = "linux")]
    async fn run_linux(&self) -> anyhow::Result<()> {
        // TODO: Implement Linux TUN device
        // Requires tun-tap crate or direct ioctl calls
        anyhow::bail!("TUN device not yet implemented for Linux")
    }

    #[cfg(target_os = "windows")]
    async fn run_windows(&self) -> anyhow::Result<()> {
        // TODO: Implement Windows TUN device
        // Requires WinTun or TAP-Windows adapter
        anyhow::bail!("TUN device not yet implemented for Windows")
    }

    #[cfg(target_os = "macos")]
    async fn run_macos(&self) -> anyhow::Result<()> {
        // TODO: Implement macOS TUN device
        anyhow::bail!("TUN device not yet implemented for macOS")
    }
}
